【摘要】 脉冲星是宇宙中最精确的时钟,其信号周期的精确度能够超过原子钟;它发出的脉冲在到达地球的过程中,如果途径黑洞附近,会被强引力场弯曲,原则上可以通过观测接收到的脉冲来研究黑洞和强引力场的性质.我们以围绕银河系中心超大质量黑洞做圆周运动的脉冲星为研究对象,分析了强引力场对脉冲路径的影响和脉冲到达时间的延迟.结果表明,脉冲轨迹和时延敏感依赖于观测者的观测倾角.观测角越大,强引力场效应就越显著.相比于黑洞的引力质量,黑洞自旋对结果的影响较小;当观测者偏离脉冲星轨道平面较大,即观测角较小时,黑洞的自旋效应明显变小;因此,需要借助高精度和灵敏度的望远镜来探究黑洞自旋的影响.更多还原

【Abstract】 Pulsar is the most accurate clock in our universe, the accuracy of its period is more than that of atomic clock. If pulse beams from pulsars pass through a black hole on their way to the Earth, they could be strongly deflected by the black hole. In principle, the received beams could be used as the probe for investigating the strong gravity near the event horizon of black hole. In this work, we investigate the effects of the strong gravity on the trajectory and time delay of pulse beams from a pulsar moving around the supermassive black hole(SMBH) which is believed to reside at the Galactic Center. Our results indicate that the trajectory and time delay sensitively depend on the observing angle. The larger the observing angle, the stronger the effects of the gravity. Compared to the gravitational mass of black hole, its spin has little effect on the trajectory and time delay of the pulse beams. If the observing angle is small, the effects of black hole spin can be neglected; therefore,future telescopes with high precision accuracy and sensitivity are needed to explore the effects of black hole spin.更多还原